Tube vendors.

I’ve been most impressed by Andy Bouwman at Vintage Tube Services. Very knowledgeable, and really cares about fitting you with the right tube for your equipment. That said.. I also get tubes from RAM tubes… and only from them for my Music Reference amps. I used Upscale Audio many times years ago, and frankly they’re hit or miss… (in my experience). Andy asked a lot of questions about my gear, and what I’m looking for in sound. He has detailed records of all kinds of specific tube gear, and how it sounds with various tubes. Great resource. 

@wolf_garcia … sorry, a tiny bit off topic, but have you tried other tubes in your Freya? If so, which, and from whom (back on topic..)? 

Andy, Kevin Deal and Brent Jesse all know what they are doing. Certainly one of the best is the guy in Wisconsin (Brendan?) and Gregg Levy at High Test in New Jersey for guitar amp (pro) tubes. 

I wouldnt buy from any dealer that says they have a bunch of: "NOS in white box" tubes. Should read "tests as NOS in white boxes".

I won't try to tell you what to buy, audition_audio, but tubes were bulk packed for industrial and military users.  So NOS tubes can come in white boxes.

Krelldreams...from the original Russian tubes I ventured into Sylvania "chrome domes," new Tung Sols, and others I can't remember but stuck with a quartet of NOS GE 6SN7GTBs which have lasted a very long time.